GB2521014A

GB2521014A - Security devices and straps therefor

Info

Publication number: GB2521014A
Application number: GB1321723.7A
Authority: GB
Inventors: Neil Anthony Barron
Original assignee: Zeal Innovation Ltd
Current assignee: Zeal Innovation Ltd
Priority date: 2013-12-09
Filing date: 2013-12-09
Publication date: 2015-06-10
Also published as: GB201321723D0

Abstract

A strap for a security device has a metallic core comprising an extensible spring which is surrounded by a flexible sleeve 14, the sleeve being extensible independently of the core such that the core is not under tension. The sleeve may comprise metallic or synthetic, e.g. elastomeric, braided yarns. The extensible spring may be in various forms e.g. a helical spring 16, flattened helical spring with elliptical cross section, an elongate element that is folded in the longitudinal direction (20 Fig 3), a plurality of springs (22 Fig 4) which resist cutting in different ways. The core may also be a mixture of springs and supplementary yarns (24 Fig 4) located either randomly or woven. As the core is not under tension, it is more difficult to cut and inhibits cutting of the sleeve. The strap may be used to secure baggage or light vehicles, by inserted a U shaped loop 8 through slot 10 and locking it in place with a padlock.

Description

SECURITY DEVICES AND STRAPS THEREFOR

This invention relates to security devices and straps for such devices. Such straps and devices can be used to secure baggage and light vehicles in the manner described in various patent publications including International Specification No: W02010/103327, and US Patent Nos: 5706679 and 6,510,717. Reference is directed to each of these documents as background material to the present invention.

The present invention is concerned with the need to provide a strap for security devices that is sufficiently resistant to cutting to so hamper a cutting process as to render it impractical to complete the process. In a strap according to the present invention a central metallic core comprises an extensible spring which is contained within a sleeve. The sleeve is extensible independently of the core such that the core is not under tension when the sleeve is extended. The spring is typically an helical spring. In one variant, a flattened helical spring can be used, which has a substantially elliptical cross-section. In either of these forms, the spring may contain a filler. In another alternative form, the spring is one which in its relaxed state, comprises an elongate element extending in a series of overlapping folds within the sleeve.

Whatever form of spring is used, it can be itself enclosed within the flexible tube which is independent of the sleeve.

The core in straps according to the invention may comprise a plurality of springs, in the same or different forms, which can be twisted, woven or braided within the sleeve. Additional or supplementary yarns can also be included if desired, provided they do not interfere with the freedom of movement of the spring or springs within the sleeve.

In preferred straps according to the invention the sleeve comprises braided yarns and these yarns can also be metallic. However, materials such as carbon fibre, synthetic fibres such as Kevlar; glass fibre; mineral fibre such as basalt, and other synthetic materials and elastomers can be used. Although normally woven, such yarns can also be knitted. The actual structure of the sleeve is though less critical, and some plastics extrusions can be sufficient. However, the selection of a material for the sleeve should take account of its function to resist stretching. In some embodiments it will provide the primary tensile strength of the strap.

To be used in a security device, a strap according to the invention will have complementary locking units at either end, with each unit being secured to the sleeve and receiving an end of the core. The length of the core is at least equal to the space in between the locking units when the sleeve is fully extended, and the ends of the core preferably remain in the respective locking units when the sleeve is fully extended.

Generally, the core will give the lacking device additional tensile strength by virtue of its ends still being held in the respective locking units when the sleeve is fully extended.

One way of accomplishing this whioe ensuring that the sleeve remains extensible independently of the core is by attaching an element formed with at least one elongate slot at each end of the core, which slot receives a pin fixed in the respective locking unit. The pin thereby allows lengthwise movement of the core relative to each locking unit corresponding to the length of the slot or slots. Another means of accomplishing this is to form a ribbon a similar element, which rib is located behind a shoulder in the respective locking unit to prevent total withdrawal of the core from the locking unit.

Other mechanisms, including elastic mechanisms, can be used to accommodate controlled extension of the strap while retaining some attachment to the core. The spring can itself be extensible in some embodiments, and direct attachment to the locking devices can therefore be acceptable in particular circumstances; for example, when extension of the sleeve is restricted.

Embodiments of this invention will now be described by way of example and with reference to the accompanying drawings wherein: FIGURE 1 is a part-broken perspective view showing a security device in accordance with the invention; FIGURES 2, 3 and 4 show alternative forms of cores for use in the strap of the device of Figure 1; and FIGURE 5 is a partly broken perspective view of another security device in accordance with the invention.

The device shown in Figure 1 consists of a strap 2 extending between two locking units 4,6. The unit 6 has two U-shaped elements 8 adapted to extend through a slot 10 in unit 4 when the device is used in the form of a loop. A padlock or other mechanism (not shown) may be used to prevent the element S from being withdrawn from the slot 10.

The strap 2 itself consists of a core 12 within a sleeve 14. Each end of the sleeve 14 is fixedly attached to a respective one of the locking units 4 and 6. The core 12 can move within the sleeve, but each end of the core 12 will also extend into a respective locking unit, The sleeve is itself extensible to some degree but not to an extent that the core withdraws at one or other end from a respective locking unit. The strap is typically around 5cms wide; its thickness will depend upon the nature of the core, but will normally be no more than 2cms.

Figure 2 illustrates the cross-section of a strap according to the invention which could be used in place of that shown in the device of Figure 1. Within the sleeve 12 the core comprises an helical spring 16. The turns in the spring 16 are closely spaced or touching, and do of course remain in this state as the sleeve is extended. The cross-section of the spring (and sleeve) can be circular, but it could be elliptical, giving the overall appearance of the strap a flatter shape. An elliptical cross-section also facilitates bending of the strap about the longitudinal axis of the ellipse.

In the strap of Figure 3 the core comprises an elongate planar body with folds overlapping in longitudinal direction. This arrangement has the advantage that the core has a thickness of at least three layers at any point along its length, and any attempt to stretch it will be resisted by the sleeve 12 which inhibits the separation of the folds.

The strap illustrated in Figure 4 is many ways similar to that in the device of Figure 1, but that the core comprises a mixture of extensible springs 22 and supplementary yarns 24 of other material or materials. The yarns and springs can be randomly intermingled, or deliberately woven, The yarns must not however, interfere with the movement of the core within the sleeve 12.

In the device illustrated in Figure 5 the core comprises a flat array of extensible springs 26; three are shown but two or more may be used. This arrangement, as in the arrangement of Figure 2, facilitates bending of the strap around lateral axes, but additionally serves to resist flexure about an axis perpendicular to the plane of the array.

In security devices of the invention the core of the strap can be loosely attached at each end to the locking units 4 and 6 to ensure that the core ends remain within the locking units even when the sleeve is extended. Various mechanisms can be used for this, as discussed above.

Claims

CLAIMS: 1. A strap for a security device in which a central metallic core comprising an extensible spring is contained within a sleeve, and wherein the sleeve is extensible independently of the core such that the core is not under tension when the sleeve is extended.
2. A strap according to Claim 1 wherein the sleeve comprises braided yarns.
3. A strap according to Claim 2 wherein the yarns are metaUic.
4. A strap according to Claim 2 wherein the yarns are formed in a synthetic material.
5. A strap according to Claim 2 wherein the synthetic material is elastomeric.
6. A strap according to Claim 1 wherein the sleeve is a plastics extrusion.
7. A strap according to any preceding Claim wherein the spring is an helical spring.
8. A strap according to any of Claims 1 to 6 wherein the spring is a flattened helical spring having a substantially elliptical cross-section.
9. A strap according to any preceding Claim wherein the space within the spring contains a filler.
10. A strap according to any of Claims I to 6 wherein the spring comprises an elongate element having a series of folds overlapping in its longitudinal direction.
11. A strap according to any preceding Claim wherein the spring is enclosed within a flexible tube independent of the sleeve.
12. A strap according to any preceding Claim wherein the core comprises a plurality of said springs.
13. A strap according to Claim 12 wherein the springs are braided within the sleeves.
14. A security device comprising a strap according to any preceding Claim with complementary locking units at either end, each unit being secured to the sleeve and receiving an end of the core, the length of the core being at east equal to the space in between the locking units when the sleeve is fully extended.
15. A security device according to Claim 14 wherein the ends of the core remain in the respective locking units when the sleeve is fully extended.
16. A security device according to Claim 14 or Claim 15 wherein an extensible coupling attaches each end of the core to the respective locking device.
17. A security device according to Claim 16 wherein the coupling is elastic.